Micro-Biology: Crash Course History of Science
German botanist Matthias Schleiden and physiologist Theodor Schwann proposed a modern cell
theory around 1837: every living thing is made up of one or more cells. They both notice tiny bot
in the middle of the cells while looking under the microscope. being able to observe single-celled
organisms didn’t immediately lead scientists to connect them with disease. In the 1800s medicine
mostly work with liquid which is called humors. But there were different types of diseases that
were caused by an invisible badness in the environment (pollution?) that is called miasma.
Miasma theory is diseases were caused by foul-smelling airs that came from rotting meats,
swamps, and other putrefying sources.
The Nucleus: Crash Course Chemistry
Chemistry is the science of how three tiny particles, the proton, the neutron, and the electron,
came together in trillions of combinations to form, everything. Einstein mathematically proved
that atoms and molecules existed in 1905. Everything we think of is made of atoms, atoms is the
Greek word for “invisible” Atoms have subatomic particles which are protons, electrons, and
neutrons. Protons is positively charge and sits inside the nucleus. Electrons are a negatively
charge with very little mass at all and is also go around the nucleus. The neutron is neutral and
sits inside the nucleus with the proton.
The Periodic Table: Crash Course Chemistry
The periodic table is a table of element, a concise, information-dense catalog of all the different
sorts of atoms in the universe. Mendeleev spent a great deal of time in laboratories as a student,
studying the burgeoning new field of chemistry. Mendeleev has identified a lot of elements we
study today which are soft, shiny extremely reactive alkali metals, so reactive they must be
stored in oil, so it doesn’t react with the atmosphere. He also identified alkaline earth metals that
are still reactive but not as reactive as the alkali metals. Transition metals are non-reactive, they
are your basic metals like iron and copper.
